# How to Modify an Existing Node

This guide demonstrates how to extend a Reth node with custom functionality, including adding RPC endpoints, modifying transaction validation, and implementing custom services.

## Adding Custom RPC Endpoints

One of the most common modifications is adding custom RPC methods to expose additional functionality.

### Basic Custom RPC Module


## Next Steps

- Explore [Standalone Components](/sdk/examples/standalone-components) for direct blockchain interaction
- Learn about [Custom Node Building](/sdk/custom-node/prerequisites) for production deployments
- Review [Type System](/sdk/typesystem/block) for working with blockchain data
